Many unknown "Frame xxxxx-xxxxx" files. Do you know what these are and can I delete them?

Asking for a friend on a more recent if not most recent Mac OS.

He has a whole bunch of files taking up a bunch of space. These files are numbered, not necessarily incrementally and named "Frame" followed by a 5 or 6 digit number, a dash and another 5 or 6 digit number.

Example filenames:
"Frame 75776 – 76799"
"Frame 290816 – 291839"

These files are in the "Documents" folder, take up a quite few dozen Gigabytes if I understand correctly and are identified by the OS as type "TextEdit.app Document"
All have the same datestamp (and relatively similar/kind of seqeuntial timestamps) and they are all 101.7 MB in size.

I’m assuming some kind of temp file or something that wasn’t cleaned up properly but idk from what. Google isn’t turning anything up and I would like to be sure before I advise he can delete them.

Anyone know what these are, how they might have come to be and if it’s safe to just delete?

Thanks much.

EDIT – I should add that the contents of the files do not appear to be text as the ‘type’ implies. They seem to be some kind of binary blob.